The present invention relates to a document transferring device for an image forming device, such as an image reading device or an image printing device, and more specifically, to an automatic document supplying device for supplying a plurality of documents stacked on a document tray by separating sheet by sheet to the image forming device, such as the image reading device.
As an example of the document transferring device for the image forming device, there has been known an automatic document supplying device for a book scanner wherein a function for reading a transferring document is added to the book scanner of a type where a stationary document is read. This type of device comprises a document placing table, document separating means disposed on one side over an ejection tray and a scanner main portion, document transferring means, and paper ejecting means, wherein a document transfer path extending to the ejection tray is rotated by 180 degrees on the way thereof, so that the document placing table and the ejection tray are disposed in a vertical relationship. In the conventional device, since the document placing table and the ejection tray are disposed in the vertical relationship, reading of the stationary document and reading of the transferring document can be carried out with a compact structure.
However, in the reading device as described above, the document does not always have an image information on one side thereof, and in many cases, the document has image information on both sides.
The conventional device as described above does not have a mechanism for automatically processing the document with the image information on both sides, and in order to process the both side document, even the automatic document supplying device is not useful, so that there are defects in an operation ability in that the both side document has to be manually reversed whenever one surface side is copied.
The present invention has been developed based on the aforementioned problems of the conventional device, and it is an object of the present invention to provide a document transferring device wherein the document is surely transferred while having the same compact structure as in the conventional device, and furthermore, various supply modes are provided to thereby obtain improved performance.